Mustang and Ford Performance Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
55 Posts
Discussion Starter · #1 ·
I am in the process of installing my KB, and am thinking about the 55# injectors. Has anybody who has done this install found an upgraded fuel rail that will fit? I had the php fuel rails on previously, and there is no way that they are going to fit under the inlet plenum of the KB. Anybody know if the round ones that Deviant Racing sells will fit?

Also, Kenne Bell is emphatic that with their chip and the boost-a-pump, the stock injectors are more than adequate. Are you guys that are going to the 55# ones doing so to avoid the use of the BAP? Or is there another reason? Whose chip are you using? I called KB about reprogramming theirs for the bigger injectors and while they didn't refuse, they insisted that it was completely unneccessary.

Any help is greatly appreciated. I am at the point where I am reassembling the lower manifold and the blower, and the fuel rails have to be in place prior to bolting everything down.

Ed
 

Attachments

·
Registered
Joined
·
4,522 Posts
They are right, at the "stock" KB levels, the stock injectors are fine. But as you start upping the HP numbers, you run out. You'll have to take off the blower to put in injectors, so most are upgrading on the install to cover future HP expansion. Some need it immediately depending on their existing mods and the boost level they pick with the KB.

Dunno about the fuel rails though..
 

·
Snake Charmer
Joined
·
2,830 Posts
I think the term more "than adequate" is likely true if supplying fuel is the only goal. Hell, I was using stock #19 and getting 300rwhp in my truck so you can FORCE a lot of extra fuel through small injectors, but that comes at a price. Injectors dont atomize the fuel as nicely when being force fed and hence it can cost you power.

According to pro-M 42's should be good to 610hp. And 50's to 727

Multiply the number of injectors by the fuel injector lbs/hr rating, divided by the brake specific fuel consumption. (BSFC). For naturally aspirated engines the BSFC range is 0.45 - 0.55 and for turbo or supercharged engines from 0.55 - 0.65. For a naturally aspirated 8 cylinder engine with 19 lb. horsepower injectors, this formula would give (8*19)/0.45 = 337 horsepower.
 

·
Registered
Joined
·
661 Posts
I have found no need to install fuel rails,.,,./,., Yet ! I may though.
I am handeling 780 hp fine with the stock rails. the stock Inj. will be fine with Kb set up , fuel rails will be verry hard to fit in that area. I put 55lb in for the cars making 600+ hp, or if they want to do this later, Boost levels of 20 ish. Also you have to tune the chip for the 55lb, I have nice snappy files , that make good power with the 55lbs. nitro
 

·
Registered
Joined
·
55 Posts
Discussion Starter · #5 ·
Pete:

I have the 9" lower on the car, so the least amount of boost I will make should be about 14.5# with the stock blower pulley according to the KB documentation. My plan was to run this on the street and then switch to a smaller pulley for the track, to make 20ish. Sounds like you think I need the 55# injectors to do this.

Are you using the Diablo chip instead of what KB sends with the kit? Are you running seperate street/track tunes? I would like to be able to use pump gas on the street (we have decent 93 octane around here)


Thanks!

Ed
 
1 - 5 of 5 Posts
Top